JP3358242B2 - Valve timing adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing controller (VVT) for changing the valve timing of an internal combustion engine according to operating conditions.

[0002]

2. Description of the Related Art As a mechanism for variably controlling the timing of opening and closing an intake valve in accordance with the operating conditions of an internal combustion engine, a valve timing adjusting device for changing the rotation phase of a camshaft with respect to a cam pulley rotating in synchronization with a crankshaft. It has been known. For example, JP-A-1-134010
As disclosed in Japanese Unexamined Patent Publication, a timing changing means provided with a hydraulic servo valve for changing the opening / closing timing (valve timing) of an intake valve of an internal combustion engine is provided.
There is known a servo valve provided with fluid pressure driving means for driving a spool of the servo valve by a hydraulic cylinder.

In this prior art, the two on-off valves provided in the fluid pressure driving means are controlled to open and close, and the servo valve is moved at a constant speed, so that the valve timing is changed by the timing changing means. ing.

[0004]

As described above, in the prior art, the structure is complicated because a hydraulic system is required for the timing changing means and the fluid pressure driving means. further,
In the above prior art, since the supply of hydraulic pressure is only interrupted by the two on-off valves, it is difficult to control a minute moving amount and a moving speed of the servo valve, and to control the valve timing by a minute amount. In addition, there has been a problem that it cannot be changed at a desired speed and more accurate control cannot be performed.

Therefore, it is conceivable to change the valve timing at a desired speed by using a valve capable of adjusting the amount of oil by adjusting the opening degree, instead of the on-off valve. However, when such a valve is used, there is a possibility that changes in the valve drive signal and the valve timing do not exactly match due to manufacturing variations of the valve, oil leakage from the valve, and the like. For example,
There are disadvantages that the valve timing cannot be maintained as it is or that the valve timing cannot be changed.

In view of the above-mentioned problems of the prior art, the present invention makes it possible to simplify the structure of the entire apparatus, and to make use of a valve capable of adjusting the amount of oil in accordance with the degree of opening even if a valve is used. It is an object of the present invention to provide a valve timing adjusting device capable of accurately controlling the valve timing without the influence of the above.

[0007]

According to the present invention, as shown in the block diagram of FIG. 12, a crankshaft member which rotates synchronously with a crankshaft and a driving force from the crankshaft member are provided. A camshaft receiving and rotating, a hydraulic piston disposed between the crankshaft member and the camshaft so as to be movable in the axial direction, and changing a phase between the crankshaft member and the camshaft; A hydraulic chamber provided in the axial direction of the piston, a hydraulic passage communicating with the hydraulic chamber, a valve provided in the hydraulic passage for adjusting an amount of oil supplied to the hydraulic chamber in accordance with an opening degree, Driving means for adjusting the degree of opening of the valve according to the input drive signal; relative rotation angle detection means for detecting a relative rotation angle between the crankshaft and the camshaft; and Camshaft and said clan Target relative rotation angle calculation means for calculating a target relative rotation angle with respect to a shaft; and the drive for matching the relative rotation angle to the target relative rotation angle based on the relative rotation angle and the target relative rotation angle. Control means for calculating a drive signal of the means, and an operation state of the hydraulic piston detected by the relative rotation angle detected by the relative rotation angle detection means, and the drive means for setting the hydraulic piston to a predetermined operation state And a learning means for learning the drive signal and correcting the drive signal calculated by the control means based on the learned value.

[0008]

According to the valve timing adjusting apparatus of the present invention described above, when the opening of the valve is adjusted by the driving means, the oil amount corresponding to the opening is supplied to the hydraulic chamber communicating with the hydraulic passage. Is done. Since the hydraulic piston moves in the axial direction according to the amount of oil, the relative rotation angle between the camshaft and the crankshaft member changes.

The control means calculates a drive signal for adjusting the opening of the valve so that the actual relative rotation angle matches the target relative rotation angle calculated according to the operating state.
Here, the learning means detects an operating state of the hydraulic piston based on the detected relative rotation angle, and learns a drive signal for setting the hydraulic piston to a predetermined operating state. For this reason,
When this learned drive signal is output to the drive means, the valve is always accurately controlled to the opening required to bring the hydraulic piston into a predetermined operating state. The learning means corrects the drive signal output from the control means based on the learned drive signal.

For this reason, the drive signal input to the drive means is a drive signal capable of reliably obtaining the operating state of the hydraulic piston required to control the relative rotation angle to the target rotation angle, and the operating state The opening degree of the valve required for the above is reliably obtained. Therefore, even when an error occurs in the relationship between the drive signal and the opening degree of the valve due to manufacturing variations of the valve or oil leakage of the valve, the opening degree of the valve is adjusted so that the relative rotation angle matches the target relative rotation angle. Is precisely controlled.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a valve timing adjusting apparatus according to the present invention will be described below with reference to the drawings. FIG.
1 is a schematic view showing an embodiment in which the present invention is applied to a double overhead cam type internal combustion engine, and FIG. 2 is a sectional view of a valve timing adjusting device.

In the internal combustion engine 1, a pair of camshafts 4 and 5 are driven by a timing chain 3 transmitting power from a crankshaft 2 via a pair of sprockets 13a and 13b. And, on the camshaft 5,
A valve timing adjusting device 40 indicated by a broken line in the figure is provided.

A crank position detecting sensor 42 is mounted on the crankshaft 2, and a cam shaft position detecting sensor 44 is mounted on the camshaft 5. Here, when the number of pulses from the crank position detection sensor 42 is N when the crankshaft 2 makes one rotation, the number of pulses from the camshaft position detection sensor 44 is 2N when the camshaft 5 makes one rotation. To do. If the maximum value of the timing conversion angle of the camshaft 5 is the θmax crank angle, N <360 degrees / θm
The number of pulses N is set to be ax. by this,
When calculating a relative rotation angle θ to be described later, a pulse from the crank position detection sensor 42 and a pulse from the camshaft position detection sensor 44 that occurs continuously after this pulse can be used.

The signals from the crank position detection sensor 42 and the cam shaft position detection sensor 44 are
6 is input. In addition to this signal, a cooling water temperature signal of the internal combustion engine 1, a throttle opening signal, and the like are input, and the control device 46
Of the camshaft 5 with respect to the crankshaft 2 based on these signals.
a is calculated. Then, the drive signal calculated by the control device 46 is input to a linear solenoid 64, which will be described later, which is an electromagnetic actuator, and drives the spool valve 30, which will be described later. By driving the spool valve 30, the oil is pumped from an oil pan 28 by an oil pump 29,
The amount of oil supplied to the valve timing adjusting device 40 is adjusted.

Hereinafter, the valve timing adjusting device 40
Will be described. In FIG. 2, a pin 1 is provided at an end of the camshaft 5 so as to rotate integrally with the camshaft 5.
A substantially cylindrical camshaft sleeve 11 fixed by 2 and bolts 10 is provided. An external helical spline 11 a is formed on a part of the outer peripheral surface of the camshaft sleeve 11. Further, the camshaft sleeve 11 is provided with a cylindrical portion 11b protruding into the housing 23 attached to the cylinder head 25 with bolts 24.

The sprocket 13a is supported by being sandwiched between the camshaft 5 and the camshaft sleeve 11, and is prevented from moving in the axial direction.
Relative rotation with respect to. On the left side of FIG. 2 of the sprocket 13a, a sprocket sleeve 15, which is a substantially cylindrical crankshaft member, is provided with a pin 14 and a bolt 1.
6 are fixed so as to rotate integrally with the sprocket 13a. Also, this sprocket sleeve 15
Is provided with a cylindrical portion 15 b protruding inside the housing 23 so as to cover the camshaft sleeve 11. An internal tooth helical spline 15a is formed on a part of the inner peripheral surface of the protruding cylindrical portion 15b.
The internal tooth helical spline 15a is formed to have a twist angle in the opposite direction to the external tooth helical spline 11a. The external tooth helical spline 11
Either “a” or the internal tooth helical spline 15 a may be a spline having a straight tooth parallel to the axial direction with a helix angle of zero.

The cylindrical portion 11b of the camshaft sleeve 11 and the cylindrical portion 15b of the sprocket sleeve 15
An annular space 90 having a substantially uniform cross-section in the axial direction is formed in a part of the gap with the space 90. In the space 90, the liquid can be slid while maintaining a liquid-tight state in the axial direction. A substantially cylindrical hydraulic piston 17 is inserted. An internal helical spline 17a meshing with the external helical spline 11a of the camshaft sleeve 11 is formed on a part of the inner surface of the hydraulic piston 17, and an internal helical spline of the sprocket sleeve 15 is formed on a part of the outer surface. An external helical spline 17b meshing with 15a is formed. Due to the meshing of the splines, the sprocket 13 is moved through the timing chain shown in FIG.
The rotation of the crankshaft 2 transmitted to a is transmitted to the camshaft 5 via the sprocket sleeve 15, the hydraulic piston 17, and the camshaft sleeve 11. Also,
An oil seal 70 is provided on the outer periphery of the collar formed at the left end of the hydraulic piston 17. The oil seal 70 is provided on the cylindrical portion 15 of the sprocket sleeve 15.
b to be in contact with the inner peripheral surface.

By providing the hydraulic piston 17 in the space 90, the space 90 is divided into two chambers. As a result, the advance hydraulic chamber 22 is formed on the left side of the hydraulic piston 17, and the retard hydraulic chamber 32 is formed on the right side of the hydraulic piston 17. The oil seal 70 ensures the sealing between the hydraulic chambers 22 and 32. An end plate 50 is attached to the left open end of the sprocket sleeve 15 in the drawing. The end plate 50 includes a cylindrical portion and a flange portion formed at the right end of the cylindrical portion in the drawing and attached to the open end of the sprocket sleeve 15. A groove is provided on the outer periphery of the cylindrical portion of the end plate 50, and the oil seal 71 is held in the groove.

An annular ring plate 51 fixed to the housing 23 by a knock pin 53 is provided at the left end of the end plate 50 and the camshaft sleeve 11. The ring plate 51 is formed in a U-shaped cross section, and has a cylindrical portion of the end plate 50,
The camshaft sleeve 11 and the cylindrical portion 11b are rotatably housed therein. Further, a groove is provided on the outer periphery of the inner cylindrical portion of the ring plate 51, and the groove is provided in the groove.
2 is retained. The oil seal 72 secures a seal between the ring plate 51 and the camshaft sleeve 11. On the other hand, the oil seal 71 secures a sealing property between the end plate 50 and the ring plate 51. Thereby, the sealing property in the advance hydraulic chamber 22 is ensured.

A bolt 52 is attached to the center opening of the ring plate 51 and the opening of the housing 23. When the bolt 52 is attached, a space 91 is formed between the inner periphery of the camshaft sleeve 11 and the camshaft 5. Further, inside the bolt 52, a hydraulic passage 61b having a T-shaped cross section communicating with the space 91 is formed. Further, an annular groove is formed on the outer periphery of the bolt 52, and both ends in the radial direction of the hydraulic passage 61b communicate with each other.

The housing 23 has the bolt 5
A hydraulic passage 61a communicating with the second annular groove is formed. The hydraulic passage 61a has a hydraulic passage 61 having a T-shaped cross section.
The space b communicates with the space 91, and the space 91 communicates with the retard hydraulic chamber 32 through a hydraulic passage 61 c formed in the camshaft sleeve 11. Further, a hydraulic passage 60 communicating with the advance hydraulic chamber 22 is formed in the housing 23. The hydraulic passages 61a and 61
0 is formed in the housing 23 and is provided with a spool valve 3 to be described later.
0 is opened in the space 95 for accommodating the “0”. In this space 95, a hydraulic supply passage 65 for supplying oil pumped from the oil pan 28 of the internal combustion engine 1 by the oil pump 29 opens, and a hydraulic release passage 66 for returning oil to the oil pan 28 opens. .

Hereinafter, the configuration of the spool valve 30 will be described with reference to FIG. 3A, 3B, and 3C,
It is sectional drawing of the spool valve 30 when switching a hydraulic path, and the operation | movement is mentioned later. The hydraulic passage 61 is provided in the cylinder 30a of the spool valve 30 housed in the space 95.
a, and a hydraulic port 30c communicating with the hydraulic passage 60 is provided. Further, the suction port 30 d communicating with the hydraulic supply path 65 and the hydraulic release path 6
6. Discharge ports 30e and 30f communicating with 6 are provided.
A spool 31 that slides inside the cylinder 30a and that switches the communication of the port is inserted into the cylinder 30a. A spring 31a for urging the spool 31 leftward in the figure is provided on the right side of the spool 31 in the figure. Further, a linear solenoid 64 acting as an electromagnetic actuator is provided on the left side of the spool 31 in the drawing. Due to the electromagnetic force generated by the linear solenoid 64, the spool 31 moves to the right in the drawing against the urging force of the spring 31a.

The operation of switching the hydraulic passage by the movement of the spool 31 in the spool valve 30 will be described below. FIG.
As shown in (a), when the spool 31 moves to the right, the suction port 30d and the hydraulic port 30c open, and the hydraulic supply path 65 and the hydraulic path 60 communicate. For this reason,
The hydraulic pressure from the oil pump 29 is supplied to the advance hydraulic chamber 22. At the same time, the discharge port 30e and the hydraulic port 30b
Is opened, and the hydraulic passage 61 and the hydraulic release passage 66 communicate with each other. Therefore, the hydraulic pressure in the retard hydraulic pressure chamber 32 is released.
As a result, the hydraulic piston 17 moves rightward, so that the camshaft 5 is advanced relative to the sprocket 13, that is, the crankshaft 2.

As shown in FIG. 3B, when the spool 31 is at the center, the hydraulic ports 30b and 30c are both closed, so that when there is no oil leakage from the hydraulic chambers 22 and 32, the hydraulic piston 17 The position is maintained, and the rotational phase of the sprocket 13 and the camshaft 5 does not change. Next, as shown in FIG. 3C, when the spool 31 moves to the left, the suction port 30d and the hydraulic port 30b open, and the hydraulic supply path 65 and the hydraulic path 61 communicate with each other. Is supplied to the retard hydraulic pressure chamber 32. On the other hand, the discharge port 30f and the hydraulic port 30
c is opened, and the hydraulic passage 60 and the hydraulic release passage 66 communicate with each other. Therefore, the hydraulic pressure in the advance hydraulic pressure chamber 22 is released.
As a result, the hydraulic piston 17 moves to the left, so that the camshaft 5 is relatively retarded with respect to the sprocket 13, that is, the crankshaft 2.

Next, the basic operation of the valve timing adjusting apparatus of this embodiment will be described with reference to the flowchart of FIG. This flowchart is obtained by extracting a step of performing feedback control of the rotation angle from the processing in the control circuit. In step 50, sensor signals from the crank position detection sensor 42 and the cam shaft position detection sensor 44 are read. Then, as shown in FIG. 4, a relative rotation angle θ between the crank position angle θ1 and the camshaft position angle θ2 is calculated based on the signals from the two sensors 42 and 44.

Next, at step 51, the camshaft 5 with respect to the crankshaft 2 corresponding to the operation state at that time is set.
And a water temperature correction duty value Tthw for correcting the deviation of the characteristic of the spool valve 30 based on the cooling water temperature. The relationship between the water temperature correction duty value Tthw and the water temperature is shown in FIG.
It becomes as shown in.

In step 52, it is determined whether or not the deviation between the relative rotation angle θ between the crankshaft 2 and the camshaft 5 and the target relative rotation angle θa is smaller than a predetermined allowable deviation Δθ. Here, if | θa−θ | ≦ Δθ, the routine proceeds to step 56, where the output duty value Td output from the microprocessor is Td = Th + Tthw
Is output as Here, Th is a learning holding duty value, and is a drive signal for bringing the hydraulic piston 17 into an operation state of holding at that position. That is, by this duty value, the relative rotation angle θ between the crankshaft 2 and the camshaft 5 is maintained as it is.
The method of learning the duty value Th will be described later.

On the other hand, if | θa−θ |> Δθ, the routine proceeds to step 53, where it is determined whether or not θa> θ. Here, when θa> θ, in step 54, the output duty value Td is output as Td = Ta + f (θa−θ) + Tthw. Here, Ta is a learning advance duty value, and is a drive signal for setting the hydraulic piston 17 to an operation state in which the hydraulic piston 17 starts to move to the advance side. That is, the duty value allows the relative rotation angle θ to start changing to the advance side. The method of learning the learning advance duty value Ta will be described later.

On the other hand, when θa ≦ θ, in step 55, the output duty value Td becomes Td = Tr + f (θa−θ) −T
thw is output. Here, Tr is a learning advance angle duty value, and is a drive signal for bringing the hydraulic piston 17 into an operating state in which it starts moving. Hydraulic piston 17
Is a drive signal for setting the operation state to start moving to the retard side. That is, the relative rotation angle θ is determined by the duty value.
Can start to change to the retard side. The method of learning the learning retard duty value Tr will be described later.

Further, f (θa−θ) in the output duty value Td in steps 54 and 55 is a deviation (θa−θ).
Is a feedback correction duty value corresponding to. This function f is a control function for performing a proportional and differential operation on the deviation (θa−θ). Note that f may be a control function including an integral operation. Thus, the relative rotation angle θ
Is feedback-controlled in the controller 46. At this time, output duty value T output from control device 46
By d, the hydraulic piston 17 moves such that the relative rotation angle θ matches the target relative rotation angle θa. When the deviation between the relative rotation angle θ and the target relative rotation angle θa falls within the allowable deviation, the output duty value is set to the sum of the learning holding duty value Th and the temperature compensation duty value Tthw. Thus, the hydraulic piston 17 is held at a position where the relative rotation angle θ becomes the target relative rotation angle θa.

FIG. 8 is a flow chart showing a learning advance duty value Ta and a learning retard duty value Tr for starting the change of the relative rotation angle θ between the crankshaft 2 and the camshaft 5. It will be described using FIG. This routine is executed together with the routine of FIG. First, a learning condition determination is performed. In step 70, it is determined whether the operating state of the internal combustion engine 1 is an idle state. If it is in the idle state, the process proceeds to step 71, and if it is in the non-idle state, the learning condition determination ends.

In step 71, when the engine is idling and stable, the deviation | θa−θ | between the predetermined target relative rotation angle θa and the relative rotation angle θ is set.
Is within a predetermined allowable deviation Δθ1. Then, when the value falls within the allowable deviation, the hydraulic piston 17
Is determined to have converged to the target relative rotation angle θa,
Proceed to step 72. On the other hand, when it is determined that θ does not converge to θa, the learning condition determination ends.

In step 72, in order to keep the relative rotation angle θ between the crankshaft 2 and the camshaft 5 as it is, the output duty value Td is calculated by adding the learning holding duty value Th and the temperature compensation duty value Tthw. Output as And this output duty value Td
Thus, when the relative rotation angle θ is held, it is determined that the learning condition is satisfied, and the learning is started.

First, at step 73, a predetermined duty value ΔTd is added to the output duty value Td. At this time, the output duty value Td is added until the spool 31 moves and the hydraulic supply path 65 and the hydraulic path 60 start to communicate with each other. Then, when the hydraulic supply passage 65 and the hydraulic passage 60 begin to communicate with each other and the amount of oil to the advance hydraulic chamber 22 increases, the hydraulic piston 17 moves to the right in FIG. 2 and the relative rotation angle θ increases. Go.

Here, in step 74, the increment .DELTA..theta.2 of the relative rotation angle .theta. During a predetermined time is detected and compared with a predetermined value .theta.A to determine whether .DELTA..theta.2≥.theta.A.
That is, it is determined whether or not the advance side moving speed of the hydraulic piston 17 has become equal to or higher than a predetermined speed, and whether or not the spool 31 of the spool valve 30 has reached a position where the hydraulic supply path 65 and the hydraulic path 60 start to communicate with each other. Judge. Also, Δθ2
When ≦ θA, the process returns to step 73 again, and adds a predetermined duty value ΔTd.

By repeating this feedback, Δθ2 ≧
θA, and when the rate of change of the relative rotation angle θ to the advance side is equal to or higher than the predetermined speed, in step 75, the output duty value Td at this time is changed to the learning advance duty value Ta.
To be stored. Thereafter, in step 76, the output duty value Td at this time is changed to a predetermined duty value ΔTd
Subtract with. At this time, the output duty value Td is decremented until the spool 31 moves and starts to communicate the hydraulic pressure supply passage 65 and the hydraulic pressure passage 61a. When the hydraulic supply passage 65 and the hydraulic passage 61a begin to communicate with each other and the amount of oil to the retard hydraulic chamber 32 increases, the hydraulic piston 17 moves to the position shown in FIG.
Moving to the middle left side, the relative rotation angle θ decreases.

In step 77, the amount of decrease Δθ2 (<0) of the relative rotation angle θ during a predetermined time is detected and compared with a predetermined value θB (<0) to determine whether Δθ2 ≦ θB. I do. That is, it is determined whether or not the retard side movement speed of the hydraulic piston 17 has become equal to or higher than a predetermined speed, and whether or not the spool 31 of the spool valve 30 has reached a position where the hydraulic supply path 65 and the hydraulic path 61a start to communicate with each other. Judge. When Δθ ≧ θB, step 76 is performed again.
And the value is subtracted by the predetermined duty value ΔTd.

By repeating this feedback, Δθ ≦ θ
B, and when the rate of change of the relative rotation angle θ to the retard side becomes equal to or greater than the predetermined rate, in step 78, the output duty value Td at this time is changed to the learning retard duty value Tr.
And In the present embodiment, the learning duty values Ta and Tr learned in the idle state are replaced by the cooling water temperature,
The learning duty value over the entire operation range is calculated by performing correction using the correction coefficient based on the rotation speed. Then, the learning duty value is set to the value in step 5 in FIG.
4, 55 are used to calculate the output duty value Td.

Here, the duty value learned in the idling state is corrected according to each operation state as in the present embodiment, and the correction value is not applied to the entire operation range. When the respective calculations are performed, there is a problem that the calculation load and the storage area of the control device increase as compared with the present embodiment. However, in the present embodiment, the learning duty value of the entire operation region can be calculated only by learning in the idle state, so that the scale of the control circuit 46 can be reduced.

By learning the learning duty values Ta and Tr, when moving the hydraulic piston 17, the spool 31 can be reliably driven until the hydraulic passages 60 and 61a start to open. And
By further moving the spool 31 from the position based on the learning duty values Ta and Tr, the amount of oil to the hydraulic chamber 22 or 32 can be reliably increased. Therefore, the moving speed of the hydraulic piston 17 can be set to a desired speed. Therefore, a change in valve timing can be controlled at a desired speed.

Also, when the driving distance of the spool 31 with respect to the output duty value changes due to manufacturing variations of the spool valve 30 or the linear solenoid 64, the change is learned by the learning control to update the learning duty value. By doing so, it is possible to reliably drive the spool 31 to a position where the oil amount starts to be supplied to the hydraulic chamber 22 or 32.

Next, a method of learning a holding duty value for holding the relative rotation angle θ between the crankshaft and the camshaft so as not to change will be described with reference to the flowchart shown in FIG. This routine is executed together with the routines shown in FIGS. In step 100, it is determined whether the operating state of the internal combustion engine 1 is an idle state. Then, in the non-idle state, the routine proceeds to step 110, where it is determined whether or not the absolute value of the deviation between the relative rotation angle θ between the crankshaft 2 and the camshaft 5 and the target relative rotation angle θa is equal to or smaller than the allowable deviation Δθ3. I do.

When the absolute value is equal to or smaller than Δθ3, the routine proceeds to step 115, where the output duty value Td
Is output as the sum of the previous learning holding duty value Th and the temperature compensation duty value Tthw. Then, in step 120, it is determined whether or not the output duty value Td has been output for a predetermined time or more. If the output duty value is equal to the output value for a predetermined time or more, step 1
Proceed to 30.

In step 130, it is determined whether the relative rotation angle θ is constant, that is, the duty value Td for a predetermined time.
It is determined whether the relative rotation angle θ has changed when is constant. If θ has not changed, the routine is terminated, assuming that the relative rotation angle θ is sufficiently held by the learning holding duty value Th at this time and the relative rotation angle θ is maintained.

On the other hand, when θ changes, step 1
At 40, it is determined whether or not it has increased from the previous relative rotation angle. When θ has increased, in step 150, the learning holding duty value Th is changed to the predetermined duty value Δ
Decrease by T. On the other hand, when θ decreases, in step 160, the learning holding duty value Th is increased by a predetermined duty value ΔT.

By repeating this processing,
The spool 31 can be reliably driven to the position where the hydraulic passages 60 and 61a are closed. Therefore, the relative rotation angle θ between the crankshaft 2 and the camshaft 5 can be reliably maintained. Further, even when oil leaks from the hydraulic chambers 22 and 32 due to manufacturing variations of the valve timing adjusting device 40 and the hydraulic piston 17 moves, an amount equal to the leakage amount is supplied to the hydraulic chamber. The learning hold duty value Th is updated, and the spool 31 is updated.
Can be controlled to that position. Therefore, the relative rotation angle θ can be always maintained.

By learning the target output duty value as described above, it is possible to eliminate problems caused by manufacturing variations of the spool valve 30 and to move the hydraulic piston 17 to an arbitrary position at a high speed and hold it. 30
Can be reliably controlled. As a result, the internal combustion engine 1 can always be operated at a desired valve timing, and fuel efficiency, emission, and output can be improved.

Further, a second embodiment of the valve timing adjusting apparatus to which the present invention is applied will be described below. In the second embodiment, instead of learning the three learning duty values Th, Ta, and Tr as in the first embodiment, only the learning holding duty value Th is learned to simplify the processing. is there. Hereinafter, the control method of the second embodiment will be described with reference to the flowchart of FIG.

In step 170, sensor signals from the crank position detection sensor 42 and the cam shaft position detection sensor 44 are read to calculate the relative rotation angle θ. next,
In step 171, a target relative rotation angle θa according to the driving state at that time is calculated. Then, in step 172,
It is determined whether or not the deviation between the relative rotation angle θ and the target relative rotation angle θa is smaller than a predetermined allowable deviation Δθ.

Here, if | θa−θ | ≦ Δθ, the routine proceeds to step 176, where the output duty value Td output from the microprocessor is output as the learning holding duty value Th. On the other hand, if | θa−θ |> Δθ, the routine proceeds to step 173, where it is determined whether or not θa> θ.

Here, when θa> θ, step 174
And the output duty value Td is calculated as Td = Th + ΔTa + f
(Θa−θ). On the other hand, when θa ≦ θ,
In step 175, the output duty value Td is set to Td = Th.
Output as −ΔTr + f (θa−θ). Note that ΔTa is a difference between a duty value for setting the hydraulic piston 17 to an operation state in which the hydraulic piston 17 starts to advance to the advance side and a learning holding duty value Th, and is a preset design value. Also, Δ
Tr is a difference between the duty value for setting the hydraulic piston 17 to an operation state in which the hydraulic piston 17 starts to move to the retard side and the learning holding duty value Th, and is also a preset design value.

Next, the process of learning the learning hold duty value Th in FIG. 10 will be described with reference to the flowchart of FIG. In step 200, the relative rotation angle θ
The absolute value of the deviation between the target relative rotation angle θa is the allowable deviation Δ
It is determined whether or not θ3 or less. When the absolute value is equal to or smaller than Δθ3, the process proceeds to step 201, and the output duty value Td of the control device 46 is held at the learning holding duty value Th set at this time.

Then, in step 202, the relative rotation angle θ
Is constant, that is, in step 201, Td held constant at a certain learning holding duty value Th
It is determined whether the relative rotation angle θ has changed. If θ has not changed, the routine is terminated on the assumption that the relative rotation angle θ is sufficiently held by Th at this time.

On the other hand, when θ changes, step 2
At 03, it is determined whether or not θ has increased from the previous value. Then, when θ increases, in step 204,
The learning holding duty value Th is reduced by a predetermined duty value ΔT. On the other hand, when θ decreases, step 20
In 5, the learning holding duty value Th is increased by a predetermined duty value ΔT.

By repeating this process, the position of the spool 31 is determined so that the relative rotation angle θ between the crankshaft 2 and the camshaft 5 can be kept constant. As described in the flowcharts of FIGS. 10 and 11, in the second embodiment, the learning holding duty value Th for holding the relative rotation angle θ at a desired position is learned. Further, when the valve timing is changed to the advance side or the retard side, the difference between the duty value for moving the spool 31 to the position where the valve timing starts to change and the learning holding duty value is set in advance. It is set to a predetermined value (ΔTa, ΔTr). This allows
While being able to hold reliably at the desired valve timing,
The processing can be simplified, and as a result, the program can be simplified.

[0056]

According to the structure and operation of the valve timing adjusting apparatus of the present invention described above, the drive signal learned by the learning means is output to the drive means, thereby bringing the hydraulic piston into a predetermined operating state. The valve is precisely controlled to the opening. Therefore, even when an error occurs due to manufacturing variations of the valve or the like, the error can be compensated and the valve can be accurately controlled to an opening degree that always brings the hydraulic piston into a predetermined operating state.

Therefore, by correcting the drive signal calculated by the control means based on the learned drive signal, the valve can be accurately controlled so that the relative rotation angle matches the target relative rotation angle. . Therefore, the control of the valve timing becomes accurate.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the valve timing adjusting device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a spool valve illustrating a switching operation of a hydraulic passage.

FIG. 4 is a time chart showing a relationship between a crank position angle and a cam shaft position angle.

FIG. 5 is a waveform chart showing an output duty value from a microprocessor.

FIG. 6 is a flowchart illustrating a control method according to the first embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between a water temperature and a water temperature correction duty value.

FIG. 8 is a flowchart for learning a learning advance duty value Ta and a learning retard duty value Tr.

FIG. 9 is a flowchart for learning a learning holding duty value Th.

FIG. 10 is a flowchart illustrating a control method according to a second embodiment.

FIG. 11 is a flowchart for learning a learning holding duty value Th according to the second embodiment.

FIG. 12 is a block diagram of the present invention.

[Explanation of symbols]

 Reference Signs List 2 crankshaft 5 camshaft 13a sprocket 11 cam sleeve 15 sprocket sleeve 17 hydraulic piston 22 advance hydraulic chamber 30 spool valve 31 spool 32 retard hydraulic chamber 42 crank position detection sensor 44 camshaft position detection sensor 46 control device 60 hydraulic Passageway 61a Hydraulic passageway 61b Hydraulic passageway 61c Hydraulic passageway 64 Linear solenoid 65 Hydraulic supply path 66 Hydraulic release path

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 13/02 F01L 1/34 F02D 11/06 F02D 45/00 340

Claims (1)

(57) [Claims] 1. A crankshaft member that rotates synchronously with a crankshaft, a camshaft that rotates by receiving a driving force from the crankshaft member, and is disposed between the crankshaft member and the camshaft so as to be axially movable. A hydraulic piston that changes a phase between the crankshaft member and the camshaft; a hydraulic chamber provided in an axial direction of the hydraulic piston; a hydraulic passage communicating with the hydraulic chamber; and a hydraulic passage provided in the hydraulic passage. A valve that adjusts the amount of oil supplied to the hydraulic chamber according to an opening degree; a driving unit that adjusts the opening degree of the valve according to a drive signal input from the outside; and the crankshaft; Relative rotation angle detection means for detecting a relative rotation angle with respect to the camshaft; target relative rotation angle calculation means for calculating a target relative rotation angle between the camshaft and the crankshaft in accordance with an operation state; Horns and the eyes Control means for calculating a drive signal of the drive means for matching the relative rotation angle to the target relative rotation angle based on the target relative rotation angle; and the relative rotation detected by the relative rotation angle detection means Learning for detecting an operating state of the hydraulic piston based on an angle, learning a driving signal of the driving unit for setting the hydraulic piston to a predetermined operating state, and correcting a driving signal calculated by the control unit based on the learning value; Means for adjusting the valve timing.